If you have a posi,you're already ahead of the game.You might want to remember,though, that if the posi unit's set up a little on the tight side,the truck may be reluctant to turn on extremely slick roads,so try to leave yourself a little room to compensate in case it wants to push a little. Usually,just starting your turn as gradually as possible will get you around corners fine. Probably won't be an issue at all.
Also,drive no faster than your defroster is capable of working...
Speed


1954 GMC 350
1957 GMC 1/2 ton
1962 Chevy C-30
1952 Chevy 6400 dump bed project truck
'98 Harley FLSTC
'66 Pontiac Catalina
'76 Chevy 1 ton Duallie
'84 Bronco II
'78 Dodge W-200
'81 Toyota 4X4 truck